'Dai Digang Wan': A Blood-Activating, Strine-Relieving Pill
Digang Wan (Expel the Storage Pill) is a Zhang Zhongjing formula from the Shanghan Lun for "lower burner blood-storage syndrome." It is composed of Shuizhi (Leech), Mengchong (Tabanid Fly), Taoren (Peach Kernel), and Dahuang (Rhubarb), and has the action of attacking and expelling static blood. It is indicated for cold damage with heat, blood stored in the lower burner, fullness in the lower abdomen, and normal urination.
The Yixue Xinwu (Mind of Medicine) records a formula called Dai Digang Wan (Substitute Di Dang Pill). Its composition is: Shengdihuang (Unprocessed Rehmannia), Danggui (Angelica), Chishao (Red Peony), each 1 liang (30 g); Chuanxiong (Sichuan Lovage Rhizome), Wulingzhi (Trogopterus Dung), each 7 qian 5 fen (22.5 g); Dahuang (Rhubarb, steamed in wine) 1 liang 5 qian (45 g). Powder all the herbs and form pills with sugar. Take 3 qian (9 g) per dose with boiling water. Dai Digang Wan resolzes stasis and promotes urination; it is indicated for blood strine (xue lin), with static blood stored and intolerable stabbing pain in the urethra. Today this formula may be used for hematuria due to inflammatory tubal infertility, traumatic constipation, bladder stones, or bladder cancer.
This formula is actually a modification of Siwu Tang (Four-Substance Decoction, made of Shengdihuang, Danggui, Chishao, and Chuanxiong). Siwu Tang is the representative formula for activating blood and resolving stasis; adding Wulingzhi strengthens its blood-activating, stasis-resolving, bleeding-stopping, and pain-relieving power. Adding Dahuang both strengthens the blood-activating effect and has a purging action, opening an exit for the pathogen. This formula combines TCM's reducing method with the purging method.
It treats hematuria of many causes, but for hematuria due to malignancy such as bladder cancer, its effect is relatively brief; when used symptomatically, it must be combined with Chinese and Western anti-cancer drugs. For hematuria, one may add Shiwei (Pyrrosia), Xianhecao (Agrimony), Qiancao (Madder), Puhuang Tan (charred Cattail Pollen), and Haijinsha (Lygodium Spores) to enhance hemostasis.
This formula may also be combined with Digang Wan for more severe lower-burner blood-storage syndrome.